Effects of Restricted Shoulder Girdle Motion on Knee Joint Kinematics and Kinetics during Walking: Cross-sectional Study.

Objectives: This study aimed to investigate the effects of restricted shoulder girdle motion on knee joint kinematics and kinetics during walking, as a preliminary step toward clarifying the role of trunk function in individuals with knee osteoarthritis. Methods: Twenty healthy male participants walked along a 7.0-m straight pathway under three conditions-neutral, flexed, and extended shoulder girdle positions-while wearing a clavicle band to restrict shoulder girdle motion. Kinematic and kinetic data for the knee joint and trunk were collected using a three-dimensional motion analysis system and a force plate. Results: In both the flexed and extended shoulder girdle positions, the ranges of motion of shoulder flexion-extension and pelvic rotation decreased. In the flexed shoulder girdle position, increased knee flexion angle was associated with a statistically significant reduction in the first peak of the external knee adduction moment (KAM), although the effect sizes were small. Conclusions: These findings suggest that experimentally manipulated restricted shoulder girdle motion is associated with significant changes in KAM. They may also provide preliminary evidence of a relationship between upper-body and lower-limb kinematics and kinetics. However, given the small effect sizes observed, these findings should be interpreted with caution.